package com.android.launcher2;
import java.util.ArrayList;
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ValueAnimator;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.os.Bundle;
import android.os.Handler;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.InputDevice;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityManager;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.animation.Interpolator;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.Scroller;

import com.george.launcher.R;

public abstract class PagedView extends ViewGroup implements ViewGroup.OnHierarchyChangeListener {
    private static final String TAG = "PagedView";
    private static final boolean DEBUG = false;
    protected static final int INVALID_PAGE = -1;

    // the min drag distance for a fling to register, to prevent random page shifts
    private static final int MIN_LENGTH_FOR_FLING = 25;

    protected static final int PAGE_SNAP_ANIMATION_DURATION = 550;
    protected static final int MAX_PAGE_SNAP_DURATION = 750;
    protected static final int SLOW_PAGE_SNAP_ANIMATION_DURATION = 950;
    protected static final float NANOTIME_DIV = 1000000000.0f;

    private static final float OVERSCROLL_ACCELERATE_FACTOR = 2;
    private static final float OVERSCROLL_DAMP_FACTOR = 0.14f;

    private static final float RETURN_TO_ORIGINAL_PAGE_THRESHOLD = 0.33f;
    // The page is moved more than halfway, automatically move to the next page on touch up.
    private static final float SIGNIFICANT_MOVE_THRESHOLD = 0.4f;

    // The following constants need to be scaled based on density. The scaled versions will be assigned to the corresponding member variables below.
    private static final int FLING_THRESHOLD_VELOCITY = 500;
    private static final int MIN_SNAP_VELOCITY = 1500;
    private static final int MIN_FLING_VELOCITY = 250;

    static final int AUTOMATIC_PAGE_SPACING = -1;

    protected int mFlingThresholdVelocity;
    protected int mMinFlingVelocity;
    protected int mMinSnapVelocity;

    protected float mDensity;
    protected float mSmoothingTime;
    protected float mTouchX;

    protected boolean mFirstLayout = true;

    protected int mCurrentPage;
    protected int mNextPage = INVALID_PAGE;
    protected int mMaxScrollX;
    protected Scroller mScroller;
    private VelocityTracker mVelocityTracker;

    private float mDownMotionX;
    protected float mLastMotionX;
    protected float mLastMotionXRemainder;
    protected float mLastMotionY;
    protected float mTotalMotionX;
    private int mLastScreenCenter = -1;
    private int[] mChildOffsets;
    private int[] mChildRelativeOffsets;
    private int[] mChildOffsetsWithLayoutScale;

    protected final static int TOUCH_STATE_REST = 0;
    protected final static int TOUCH_STATE_SCROLLING = 1;
    protected final static int TOUCH_STATE_PREV_PAGE = 2;
    protected final static int TOUCH_STATE_NEXT_PAGE = 3;
    protected final static float ALPHA_QUANTIZE_LEVEL = 0.0001f;

    protected int mTouchState = TOUCH_STATE_REST;
    protected boolean mForceScreenScrolled = false;

    protected OnLongClickListener mLongClickListener;

    protected boolean mAllowLongPress = true;

    protected int mTouchSlop;
    private int mPagingTouchSlop;
    private int mMaximumVelocity;
    private int mMinimumWidth;
    protected int mPageSpacing;
    protected int mPageLayoutPaddingTop;
    protected int mPageLayoutPaddingBottom;
    protected int mPageLayoutPaddingLeft;
    protected int mPageLayoutPaddingRight;
    protected int mPageLayoutWidthGap;
    protected int mPageLayoutHeightGap;
    protected int mCellCountX = 0;
    protected int mCellCountY = 0;
    protected boolean mCenterPagesVertically;
    protected boolean mAllowOverScroll = true;
    protected int mUnboundedScrollX;
    protected int[] mTempVisiblePagesRange = new int[2];
    protected boolean mForceDrawAllChildrenNextFrame;

    // mOverScrollX is equal to getScrollX() when we're within the normal scroll range. Otherwise
    // it is equal to the scaled overscroll position. We use a separate value so as to prevent the screens from continuing to translate beyond the normal bounds.
    protected int mOverScrollX;

    // parameter that adjusts the layout to be optimized for pages with that scale factor
    protected float mLayoutScale = 1.0f;

    protected static final int INVALID_POINTER = -1;

    protected int mActivePointerId = INVALID_POINTER;

    private PageSwitchListener mPageSwitchListener;

    protected ArrayList<Boolean> mDirtyPageContent;

    // If true, syncPages and syncPageItems will be called to refresh pages
    protected boolean mContentIsRefreshable = true;

    // If true, modify alpha of neighboring pages as user scrolls left/right
    protected boolean mFadeInAdjacentScreens = true;

    // It true, use a different slop parameter (pagingTouchSlop = 2 * touchSlop) for deciding to switch to a new page
    protected boolean mUsePagingTouchSlop = true;

    // If true, the subclass should directly update scrollX itself in its computeScroll method (SmoothPagedView does this)
    protected boolean mDeferScrollUpdate = false;

    protected boolean mIsPageMoving = false;

    // All syncs and layout passes are deferred until data is ready.
    protected boolean mIsDataReady = false;

    // Scrolling indicator
    private ValueAnimator mScrollIndicatorAnimator;
    private View mScrollIndicator;
    private int mScrollIndicatorPaddingLeft;
    private int mScrollIndicatorPaddingRight;
    private boolean mHasScrollIndicator = true;
    private boolean mShouldShowScrollIndicator = false;
    private boolean mShouldShowScrollIndicatorImmediately = false;
    protected static final int sScrollIndicatorFadeInDuration = 150;
    protected static final int sScrollIndicatorFadeOutDuration = 650;
    protected static final int sScrollIndicatorFlashDuration = 650;
    private boolean mScrollingPaused = false;
    
    private LinearLayout mScrollIndicatorBg;

    // If set, will defer loading associated pages until the scrolling settles
    private boolean mDeferLoadAssociatedPagesUntilScrollCompletes;

    public interface PageSwitchListener {
        void onPageSwitch(View newPage, int newPageIndex);
    }

    public PagedView(Context context) {
        this(context, null);
    }

    public PagedView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public PagedView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.PagedView, defStyle, 0);
        setPageSpacing(a.getDimensionPixelSize(R.styleable.PagedView_pageSpacing, 0));
        mPageLayoutPaddingTop = a.getDimensionPixelSize(R.styleable.PagedView_pageLayoutPaddingTop, 0);
        mPageLayoutPaddingBottom = a.getDimensionPixelSize(R.styleable.PagedView_pageLayoutPaddingBottom, 0);
        mPageLayoutPaddingLeft = a.getDimensionPixelSize(R.styleable.PagedView_pageLayoutPaddingLeft, 0);
        mPageLayoutPaddingRight = a.getDimensionPixelSize(R.styleable.PagedView_pageLayoutPaddingRight, 0);
        mPageLayoutWidthGap = a.getDimensionPixelSize(R.styleable.PagedView_pageLayoutWidthGap, 0);
        mPageLayoutHeightGap = a.getDimensionPixelSize(R.styleable.PagedView_pageLayoutHeightGap, 0);
        mScrollIndicatorPaddingLeft = a.getDimensionPixelSize(R.styleable.PagedView_scrollIndicatorPaddingLeft, 0);
        mScrollIndicatorPaddingRight = a.getDimensionPixelSize(R.styleable.PagedView_scrollIndicatorPaddingRight, 0);
        a.recycle();

        setHapticFeedbackEnabled(false);
        IntentFilter filter = new IntentFilter();
        filter.addDataScheme("package");
        filter.addAction("android.intent.action.PACKAGE_INSTALL");
        filter.addAction("android.intent.action.PACKAGE_ADDED");
        filter.addAction("android.intent.action.PACKAGE_REMOVED");
        context.registerReceiver(mReceiver, filter);
        init();
    }
    
    BroadcastReceiver mReceiver = new BroadcastReceiver() {
		@Override
		public void onReceive(Context arg0, Intent arg1) {
			Log.e(TAG, "get Action = "+arg1.getAction());
			Handler handler = new Handler();
			handler.postDelayed(new Runnable() {
				@Override
				public void run() {
					updateScrollingIndicatorBg();
					
				}
			}, 1000);
		}
	};

    /*** Initializes various states for this workspace. */
    protected void init() {
        mDirtyPageContent = new ArrayList<Boolean>();
        mDirtyPageContent.ensureCapacity(32);
        mScroller = new Scroller(getContext(), new ScrollInterpolator());
        mCurrentPage = 0;
        mCenterPagesVertically = true;

        final ViewConfiguration configuration = ViewConfiguration.get(getContext());
        mTouchSlop = configuration.getScaledTouchSlop();
        mPagingTouchSlop = configuration.getScaledPagingTouchSlop();
        mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
        mDensity = getResources().getDisplayMetrics().density;

        mFlingThresholdVelocity = (int) (FLING_THRESHOLD_VELOCITY * mDensity);
        mMinFlingVelocity = (int) (MIN_FLING_VELOCITY * mDensity);
        mMinSnapVelocity = (int) (MIN_SNAP_VELOCITY * mDensity);
        setOnHierarchyChangeListener(this);
    }

    public void setPageSwitchListener(PageSwitchListener pageSwitchListener) {
        mPageSwitchListener = pageSwitchListener;
        if (mPageSwitchListener != null) {
            mPageSwitchListener.onPageSwitch(getPageAt(mCurrentPage), mCurrentPage);
        }
    }
    /**
     * Note: this is a reimplementation of View.isLayoutRtl() since that is currently hidden api.
     */
    public boolean isLayoutRtl() {
        return (getLayoutDirection() == LAYOUT_DIRECTION_RTL);
    }
    
    /** Called by subclasses to mark that data is ready, and that we can begin loading and laying  out pages. */
    protected void setDataIsReady() {
        mIsDataReady = true;
    }
    
    protected boolean isDataReady() {
        return mIsDataReady;
    }

    /**
     * Returns the index of the currently displayed page.
     * @return The index of the currently displayed page.
     */
    int getCurrentPage() {
        return mCurrentPage;
    }
    int getNextPage() {
        return (mNextPage != INVALID_PAGE) ? mNextPage : mCurrentPage;
    }

    int getPageCount() {
        return 1;
    }

    View getPageAt(int index) {
        return getChildAt(index);
    }

    protected int indexToPage(int index) {
        return index;
    }

    /** Updates the scroll of the current page immediately to its final scroll position.  We use this in CustomizePagedView to allow tabs to share the same PagedView while resetting the scroll of  the previous tab page. */
    protected void updateCurrentPageScroll() {
        // If the current page is invalid, just reset the scroll position to zero
        int newX = 0;
        if (0 <= mCurrentPage && mCurrentPage < getPageCount()) {
            int offset = getChildOffset(mCurrentPage);
            int relOffset = getRelativeChildOffset(mCurrentPage);
            newX = offset - relOffset;
        }
        scrollTo(newX, 0);
        mScroller.setFinalX(newX);
        mScroller.forceFinished(true);
    }

    /**
     * Called during AllApps/Home transitions to avoid unnecessary work. When that other animation
     * ends, {@link #resumeScrolling()} should be called, along with
     * {@link #updateCurrentPageScroll()} to correctly set the final state and re-enable scrolling.
     */
    void pauseScrolling() {
        mScroller.forceFinished(true);
        cancelScrollingIndicatorAnimations();
        mScrollingPaused = true;
    }

    /**
     * Enables scrolling again.
     * @see #pauseScrolling()
     */
    void resumeScrolling() {
        mScrollingPaused = false;
    }
    /**
     * Sets the current page.
     */
    void setCurrentPage(int currentPage) {
        if (!mScroller.isFinished()) {
            mScroller.abortAnimation();
        }
        // don't introduce any checks like mCurrentPage == currentPage here-- if we change the  the default
        if (getChildCount() == 0) {
            return;
        }

        mCurrentPage = Math.max(0, Math.min(currentPage, getPageCount() - 1));
        updateCurrentPageScroll();
        updateScrollingIndicator();
        notifyPageSwitchListener();
        invalidate();
    }

    protected void notifyPageSwitchListener() {
        if (mPageSwitchListener != null) {
            mPageSwitchListener.onPageSwitch(getPageAt(mCurrentPage), mCurrentPage);
        }
    }

    protected void pageBeginMoving() {
        if (!mIsPageMoving) {
            mIsPageMoving = true;
            onPageBeginMoving();
        }
    }

    protected void pageEndMoving() {
        if (mIsPageMoving) {
            mIsPageMoving = false;
            onPageEndMoving();
        }
    }

    protected boolean isPageMoving() {
        return mIsPageMoving;
    }

    // a method that subclasses can override to add behavior
    protected void onPageBeginMoving() {
    }

    // a method that subclasses can override to add behavior
    protected void onPageEndMoving() {
    }

    /**
     * Registers the specified listener on each page contained in this workspace.
     * @param l The listener used to respond to long clicks.
     */
    @Override
    public void setOnLongClickListener(OnLongClickListener l) {
        mLongClickListener = l;
        final int count = getPageCount();
        for (int i = 0; i < count; i++) {
            getPageAt(i).setOnLongClickListener(l);
        }
    }

    @Override
    public void scrollBy(int x, int y) {
        scrollTo(mUnboundedScrollX + x, getScrollY() + y);
    }

    @Override
    public void scrollTo(int x, int y) {
        final boolean isRtl = isLayoutRtl();
        mUnboundedScrollX = x;
        boolean isXBeforeFirstPage = isRtl ? (x > mMaxScrollX) : (x < 0);
        boolean isXAfterLastPage = isRtl ? (x < 0) : (x > mMaxScrollX);
        if (isXBeforeFirstPage) {
            super.scrollTo(0, y);
            if (mAllowOverScroll) {
                if (isRtl) {
                    overScroll(x - mMaxScrollX);
                } else {
                    overScroll(x);
                }
            }
        } else if (isXAfterLastPage) {
            super.scrollTo(mMaxScrollX, y);
            if (mAllowOverScroll) {
                if (isRtl) {
                    overScroll(x);
                } else {
                    overScroll(x - mMaxScrollX);
                }
            }
        } else {
            mOverScrollX = x;
            super.scrollTo(x, y);
        }

        mTouchX = x;
        mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
    }

    // we moved this functionality to a helper function so SmoothPagedView can reuse it
    protected boolean computeScrollHelper() {
        if (mScroller.computeScrollOffset()) {
            // Don't bother scrolling if the page does not need to be moved
            if (getScrollX() != mScroller.getCurrX() || getScrollY() != mScroller.getCurrY() || mOverScrollX != mScroller.getCurrX()) {
                scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
            }
            invalidate();
            return true;
        } else if (mNextPage != INVALID_PAGE) {
            mCurrentPage = Math.max(0, Math.min(mNextPage, getPageCount() - 1));
            mNextPage = INVALID_PAGE;
            notifyPageSwitchListener();

            // Load the associated pages if necessary
            if (mDeferLoadAssociatedPagesUntilScrollCompletes) {
                loadAssociatedPages(mCurrentPage);
                mDeferLoadAssociatedPagesUntilScrollCompletes = false;
            }

            // We don't want to trigger a page end moving unless the page has settled and the user has stopped scrolling
            if (mTouchState == TOUCH_STATE_REST) {
                pageEndMoving();
            }

            // Notify the user when the page changes
            AccessibilityManager accessibilityManager = (AccessibilityManager)getContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
            if (accessibilityManager.isEnabled()) {
                AccessibilityEvent ev = AccessibilityEvent.obtain(AccessibilityEvent.TYPE_VIEW_SCROLLED);
                ev.getText().add(getCurrentPageDescription());
                sendAccessibilityEventUnchecked(ev);
            }
            return true;
        }
        return false;
    }

    @Override
    public void computeScroll() {
        computeScrollHelper();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (!mIsDataReady) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            return;
        }

        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        final int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        int heightSize = MeasureSpec.getSize(heightMeasureSpec);
        if (widthMode != MeasureSpec.EXACTLY) {
            throw new IllegalStateException("Workspace can only be used in EXACTLY mode.");
        }

        // Return early if we aren't given a proper dimension
        if (widthSize <= 0 || heightSize <= 0) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            return;
        }

        /* Allow the height to be set as WRAP_CONTENT. This allows the particular case of the All apps view on XLarge displays to not take up more space then it needs. Width is still not allowed to be set as WRAP_CONTENT since many parts of the code expect each page to have the same width.  */
        int maxChildHeight = 0;

        final int verticalPadding = getPaddingTop() + getPaddingBottom();
        final int horizontalPadding = getPaddingLeft() + getPaddingRight();


        // The children are given the same width and height as the workspace
        // unless they were set to WRAP_CONTENT
        if (DEBUG) Log.d(TAG, "PagedView.onMeasure(): " + widthSize + ", " + heightSize);
        final int childCount = getChildCount();
        for (int i = 0; i < childCount; i++) {
            // disallowing padding in paged view (just pass 0)
            final View child = getPageAt(i);
            final LayoutParams lp = (LayoutParams) child.getLayoutParams();

            int childWidthMode;
            if (lp.width == LayoutParams.WRAP_CONTENT) {
                childWidthMode = MeasureSpec.AT_MOST;
            } else {
                childWidthMode = MeasureSpec.EXACTLY;
            }

            int childHeightMode;
            if (lp.height == LayoutParams.WRAP_CONTENT) {
                childHeightMode = MeasureSpec.AT_MOST;
            } else {
                childHeightMode = MeasureSpec.EXACTLY;
            }

            final int childWidthMeasureSpec =
                MeasureSpec.makeMeasureSpec(widthSize - horizontalPadding, childWidthMode);
            final int childHeightMeasureSpec =
                MeasureSpec.makeMeasureSpec(heightSize - verticalPadding, childHeightMode);

            child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
            maxChildHeight = Math.max(maxChildHeight, child.getMeasuredHeight());
            if (DEBUG) Log.d(TAG, "\tmeasure-child" + i + ": " + child.getMeasuredWidth() + ", "
                    + child.getMeasuredHeight());
        }

        if (heightMode == MeasureSpec.AT_MOST) {
            heightSize = maxChildHeight + verticalPadding;
        }

        setMeasuredDimension(widthSize, heightSize);

        // We can't call getChildOffset/getRelativeChildOffset until we set the measured dimensions. We also wait until we set the measured dimensions before flushing the cache as well, to ensure that the cache is filled with good values.
        invalidateCachedOffsets();

        if (childCount > 0) {
            if (DEBUG) Log.d(TAG, "getRelativeChildOffset(): " + getMeasuredWidth() + ", " + getChildWidth(0));

            // Calculate the variable page spacing if necessary
            if (mPageSpacing == AUTOMATIC_PAGE_SPACING) {
                // The gap between pages in the PagedView should be equal to the gap from the page to the edge of the screen (so it is not visible in the current screen).  To account for unequal padding on each side of the paged view, we take the maximum of the left/right gap and use that as the gap between each page.
                int offset = getRelativeChildOffset(0);
                int spacing = Math.max(offset, widthSize - offset - getChildAt(0).getMeasuredWidth());
                setPageSpacing(spacing);
            }
        }

        updateScrollingIndicatorPosition();

        if (childCount > 0) {
            final int index = isLayoutRtl() ? 0 : childCount - 1;
            mMaxScrollX = getChildOffset(index) - getRelativeChildOffset(index);
        } else {
            mMaxScrollX = 0;
        }
    }

    protected void scrollToNewPageWithoutMovingPages(int newCurrentPage) {
        int newX = getChildOffset(newCurrentPage) - getRelativeChildOffset(newCurrentPage);
        int delta = newX - getScrollX();

        final int pageCount = getChildCount();
        for (int i = 0; i < pageCount; i++) {
            View page = (View) getPageAt(i);
            page.setX(page.getX() + delta);
        }
        setCurrentPage(newCurrentPage);
    }

    // A layout scale of 1.0f assumes that the pages, in their unshrunken state, have a scale of 1.0f. A layout scale of 0.8f assumes the pages have a scale of 0.8f, and tightens the layout accordingly
    public void setLayoutScale(float childrenScale) {
        mLayoutScale = childrenScale;
        invalidateCachedOffsets();

        // Now we need to do a re-layout, but preserving absolute X and Y coordinates
        int childCount = getChildCount();
        float childrenX[] = new float[childCount];
        float childrenY[] = new float[childCount];
        for (int i = 0; i < childCount; i++) {
            final View child = getPageAt(i);
            childrenX[i] = child.getX();
            childrenY[i] = child.getY();
        }
        // Trigger a full re-layout (never just call onLayout directly!)
        int widthSpec = MeasureSpec.makeMeasureSpec(getMeasuredWidth(), MeasureSpec.EXACTLY);
        int heightSpec = MeasureSpec.makeMeasureSpec(getMeasuredHeight(), MeasureSpec.EXACTLY);
        requestLayout();
        measure(widthSpec, heightSpec);
        layout(getLeft(), getTop(), getRight(), getBottom());
        for (int i = 0; i < childCount; i++) {
            final View child = getPageAt(i);
            child.setX(childrenX[i]);
            child.setY(childrenY[i]);
        }

        // Also, the page offset has changed  (since the pages are now smaller); update the page offset, but again preserving absolute X and Y coordinates
        scrollToNewPageWithoutMovingPages(mCurrentPage);
    }

    public void setPageSpacing(int pageSpacing) {
        mPageSpacing = pageSpacing;
        invalidateCachedOffsets();
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        if (!mIsDataReady) {
            return;
        }

        if (DEBUG) Log.d(TAG, "PagedView.onLayout()");
        final int verticalPadding = getPaddingTop() + getPaddingBottom();
        final int childCount = getChildCount();
        final boolean isRtl = isLayoutRtl();
        final int startIndex = isRtl ? childCount - 1 : 0;
        final int endIndex = isRtl ? -1 : childCount;
        final int delta = isRtl ? -1 : 1;
        int childLeft = getRelativeChildOffset(startIndex);
        for (int i = startIndex; i != endIndex; i += delta) {
            final View child = getPageAt(i);
            if (child.getVisibility() != View.GONE) {
                final int childWidth = getScaledMeasuredWidth(child);
                final int childHeight = child.getMeasuredHeight();
                int childTop = getPaddingTop();
                if (mCenterPagesVertically) {
                    childTop += ((getMeasuredHeight() - verticalPadding) - childHeight) / 2;
                }

                if (DEBUG) Log.d(TAG, "\tlayout-child" + i + ": " + childLeft + ", " + childTop);
                child.layout(childLeft, childTop, childLeft + child.getMeasuredWidth(), childTop + childHeight);
                childLeft += childWidth + mPageSpacing;
            }
        }

        if (mFirstLayout && mCurrentPage >= 0 && mCurrentPage < getChildCount()) {
            setHorizontalScrollBarEnabled(false);
            updateCurrentPageScroll();
            setHorizontalScrollBarEnabled(true);
            mFirstLayout = false;
        }
    }

    protected void screenScrolled(int screenCenter) {
        if (isScrollingIndicatorEnabled()) {
            updateScrollingIndicator();
        }
        boolean isInOverscroll = mOverScrollX < 0 || mOverScrollX > mMaxScrollX;

        if (mFadeInAdjacentScreens && !isInOverscroll) {
            for (int i = 0; i < getChildCount(); i++) {
                View child = getChildAt(i);
                if (child != null) {
                    float scrollProgress = getScrollProgress(screenCenter, child, i);
                    float alpha = 1 - Math.abs(scrollProgress);
                    child.setAlpha(alpha);
                }
            }
            invalidate();
        }
    }

    @Override
    public void onChildViewAdded(View parent, View child) {
        // This ensures that when children are added, they get the correct transforms / alphas in accordance with any scroll effects.
        mForceScreenScrolled = true;
        invalidate();
        invalidateCachedOffsets();
    }

    @Override
    public void onChildViewRemoved(View parent, View child) {
    }

    protected void invalidateCachedOffsets() {
        int count = getChildCount();
        if (count == 0) {
            mChildOffsets = null;
            mChildRelativeOffsets = null;
            mChildOffsetsWithLayoutScale = null;
            return;
        }

        mChildOffsets = new int[count];
        mChildRelativeOffsets = new int[count];
        mChildOffsetsWithLayoutScale = new int[count];
        for (int i = 0; i < count; i++) {
            mChildOffsets[i] = -1;
            mChildRelativeOffsets[i] = -1;
            mChildOffsetsWithLayoutScale[i] = -1;
        }
    }

    protected int getChildOffset(int index) {
        final boolean isRtl = isLayoutRtl();
        int[] childOffsets = Float.compare(mLayoutScale, 1f) == 0 ?
                mChildOffsets : mChildOffsetsWithLayoutScale;

        if (childOffsets != null && childOffsets[index] != -1) {
            return childOffsets[index];
        } else {
            if (getChildCount() == 0)
                return 0;
            final int startIndex = isRtl ? getChildCount() - 1 : 0;
            final int endIndex = isRtl ? index : index;
            final int delta = isRtl ? -1 : 1;
            int offset = getRelativeChildOffset(startIndex);
            for (int i = startIndex; i != endIndex; i += delta) {
                offset += getScaledMeasuredWidth(getPageAt(i)) + mPageSpacing;
            }
            if (childOffsets != null) {
                childOffsets[index] = offset;
            }
            return offset;
        }
    }

    protected int getRelativeChildOffset(int index) {
        if (mChildRelativeOffsets != null && mChildRelativeOffsets[index] != -1) {
            return mChildRelativeOffsets[index];
        } else {
            final int padding = getPaddingLeft() + getPaddingRight();
            final int offset = getPaddingLeft() + (getMeasuredWidth() - padding - getChildWidth(index)) / 2;
            if (mChildRelativeOffsets != null) {
                mChildRelativeOffsets[index] = offset;
            }
            return offset;
        }
    }

    protected int getScaledMeasuredWidth(View child) {
        // This functions are called enough times that it actually makes a difference in the profiler -- so just inline the max() here
        final int measuredWidth = child.getMeasuredWidth();
        final int minWidth = mMinimumWidth;
        final int maxWidth = (minWidth > measuredWidth) ? minWidth : measuredWidth;
        return (int) (maxWidth * mLayoutScale + 0.5f);
    }

    protected void getVisiblePages(int[] range) {
        final boolean isRtl = isLayoutRtl();
        final int pageCount = getChildCount();

        if (pageCount > 0) {
            final int screenWidth = getMeasuredWidth();
            int leftScreen = isRtl ? pageCount - 1 : 0;
            int rightScreen = 0;
            int endIndex = isRtl ? 0 : pageCount - 1;
            int delta = isRtl ? -1 : 1;
            View currPage = getPageAt(leftScreen);
            while (leftScreen != endIndex && currPage.getX() + currPage.getWidth() - currPage.getPaddingRight() < getScrollX()) {
                leftScreen += delta;
                currPage = getPageAt(leftScreen);
            }
            rightScreen = leftScreen;
            currPage = getPageAt(rightScreen + delta);
            while (rightScreen != endIndex && currPage.getX() - currPage.getPaddingLeft() < getScrollX() + screenWidth) {
                rightScreen += delta;
                currPage = getPageAt(rightScreen + delta);
            }
            range[0] = Math.min(leftScreen, rightScreen);
            range[1] = Math.max(leftScreen, rightScreen);
        } else {
            range[0] = -1;
            range[1] = -1;
        }
    }

    protected boolean shouldDrawChild(View child) {
        return child.getAlpha() > 0;
    }

    @Override
    protected void dispatchDraw(Canvas canvas) {
        int halfScreenSize = getMeasuredWidth() / 2;
        // mOverScrollX is equal to getScrollX() when we're within the normal scroll range. Otherwise it is equal to the scaled overscroll position.
        int screenCenter = mOverScrollX + halfScreenSize;

        if (screenCenter != mLastScreenCenter || mForceScreenScrolled) {
            // set mForceScreenScrolled before calling screenScrolled so that screenScrolled can set it for the next frame
            mForceScreenScrolled = false;
            screenScrolled(screenCenter);
            mLastScreenCenter = screenCenter;
        }

        // Find out which screens are visible; as an optimization we only call draw on them
        final int pageCount = getChildCount();
        if (pageCount > 0) {
            getVisiblePages(mTempVisiblePagesRange);
            final int leftScreen = mTempVisiblePagesRange[0];
            final int rightScreen = mTempVisiblePagesRange[1];
            if (leftScreen != -1 && rightScreen != -1) {
                final long drawingTime = getDrawingTime();
                // Clip to the bounds
                canvas.save();
                canvas.clipRect(getScrollX(), getScrollY(), getScrollX() + getRight() - getLeft(), getScrollY() + getBottom() - getTop());

                for (int i = getChildCount() - 1; i >= 0; i--) {
                    final View v = getPageAt(i);
                    if (mForceDrawAllChildrenNextFrame || (leftScreen <= i && i <= rightScreen && shouldDrawChild(v))) {
                        drawChild(canvas, v, drawingTime);
                    }
                }
                mForceDrawAllChildrenNextFrame = false;
                canvas.restore();
            }
        }
    }

    @Override
    public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
        int page = indexToPage(indexOfChild(child));
        if (page != mCurrentPage || !mScroller.isFinished()) {
            snapToPage(page);
            return true;
        }
        return false;
    }

    @Override
    protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
        int focusablePage;
        if (mNextPage != INVALID_PAGE) {
            focusablePage = mNextPage;
        } else {
            focusablePage = mCurrentPage;
        }
        View v = getPageAt(focusablePage);
        if (v != null) {
            return v.requestFocus(direction, previouslyFocusedRect);
        }
        return false;
    }

    @Override
    public boolean dispatchUnhandledMove(View focused, int direction) {
        if (direction == View.FOCUS_LEFT) {
            if (getCurrentPage() > 0) {
                snapToPage(getCurrentPage() - 1);
                return true;
            }
        } else if (direction == View.FOCUS_RIGHT) {
            if (getCurrentPage() < getPageCount() - 1) {
                snapToPage(getCurrentPage() + 1);
                return true;
            }
        }
        return super.dispatchUnhandledMove(focused, direction);
    }

    @Override
    public void addFocusables(ArrayList<View> views, int direction, int focusableMode) {
        if (mCurrentPage >= 0 && mCurrentPage < getPageCount()) {
            getPageAt(mCurrentPage).addFocusables(views, direction, focusableMode);
        }
        if (direction == View.FOCUS_LEFT) {
            if (mCurrentPage > 0) {
                getPageAt(mCurrentPage - 1).addFocusables(views, direction, focusableMode);
            }
        } else if (direction == View.FOCUS_RIGHT){
            if (mCurrentPage < getPageCount() - 1) {
                getPageAt(mCurrentPage + 1).addFocusables(views, direction, focusableMode);
            }
        }
    }

    /**
     * If one of our descendant views decides that it could be focused now, only pass that along if it's on the current page.
     * This happens when live folders requery, and if they're off page, they end up calling requestFocus, which pulls it on page.
     */
    @Override
    public void focusableViewAvailable(View focused) {
        View current = getPageAt(mCurrentPage);
        View v = focused;
        while (true) {
            if (v == current) {
                super.focusableViewAvailable(focused);
                return;
            }
            if (v == this) {
                return;
            }
            ViewParent parent = v.getParent();
            if (parent instanceof View) {
                v = (View)v.getParent();
            } else {
                return;
            }
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
        if (disallowIntercept) {
            // We need to make sure to cancel our long press if a scrollable widget takes over touch events
            final View currentPage = getPageAt(mCurrentPage);
            currentPage.cancelLongPress();
        }
        super.requestDisallowInterceptTouchEvent(disallowIntercept);
    }

    /**
     * Return true if a tap at (x, y) should trigger a flip to the previous page.
     */
    protected boolean hitsPreviousPage(float x, float y) {
        if (isLayoutRtl()) {
            return (x > (getMeasuredWidth() - getRelativeChildOffset(mCurrentPage) + mPageSpacing));
        } else {
            return (x < getRelativeChildOffset(mCurrentPage) - mPageSpacing);
        }
    }
    /**
     * Return true if a tap at (x, y) should trigger a flip to the next page.
     */
    protected boolean hitsNextPage(float x, float y) {
        if (isLayoutRtl()) {
            return (x < getRelativeChildOffset(mCurrentPage) - mPageSpacing);
        } else {
            return (x > (getMeasuredWidth() - getRelativeChildOffset(mCurrentPage) + mPageSpacing));
        }
    }
    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        /*
         * This method JUST determines whether we want to intercept the motion.
         * If we return true, onTouchEvent will be called and we do the actual
         * scrolling there.
         */
        acquireVelocityTrackerAndAddMovement(ev);

        // Skip touch handling if there are no pages to swipe
        if (getChildCount() <= 0) return super.onInterceptTouchEvent(ev);

        /*
         * Shortcut the most recurring case: the user is in the dragging
         * state and he is moving his finger.  We want to intercept this
         * motion.
         */
        final int action = ev.getAction();
        if ((action == MotionEvent.ACTION_MOVE) &&
                (mTouchState == TOUCH_STATE_SCROLLING)) {
            return true;
        }

        switch (action & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_MOVE: {
                /*
                 * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
                 * whether the user has moved far enough from his original down touch.
                 */
                if (mActivePointerId != INVALID_POINTER) {
                    determineScrollingStart(ev);
                    break;
                }
                // if mActivePointerId is INVALID_POINTER, then we must have missed an ACTION_DOWN
                // event. in that case, treat the first occurence of a move event as a ACTION_DOWN
                // i.e. fall through to the next case (don't break)
                // (We sometimes miss ACTION_DOWN events in Workspace because it ignores all events
                // while it's small- this was causing a crash before we checked for INVALID_POINTER)
            }

            case MotionEvent.ACTION_DOWN: {
                final float x = ev.getX();
                final float y = ev.getY();
                // Remember location of down touch
                mDownMotionX = x;
                mLastMotionX = x;
                mLastMotionY = y;
                mLastMotionXRemainder = 0;
                mTotalMotionX = 0;
                mActivePointerId = ev.getPointerId(0);
                mAllowLongPress = true;

                /*
                 * If being flinged and user touches the screen, initiate drag;
                 * otherwise don't.  mScroller.isFinished should be false when
                 * being flinged.
                 */
                final int xDist = Math.abs(mScroller.getFinalX() - mScroller.getCurrX());
                final boolean finishedScrolling = (mScroller.isFinished() || xDist < mTouchSlop);
                if (finishedScrolling) {
                    mTouchState = TOUCH_STATE_REST;
                    mScroller.abortAnimation();
                } else {
                    mTouchState = TOUCH_STATE_SCROLLING;
                }

                // check if this can be the beginning of a tap on the side of the pages
                // to scroll the current page
                if (mTouchState != TOUCH_STATE_PREV_PAGE && mTouchState != TOUCH_STATE_NEXT_PAGE) {
                    if (getChildCount() > 0) {
                        if (hitsPreviousPage(x, y)) {
                            mTouchState = TOUCH_STATE_PREV_PAGE;
                        } else if (hitsNextPage(x, y)) {
                            mTouchState = TOUCH_STATE_NEXT_PAGE;
                        }
                    }
                }
                break;
            }

            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
                mTouchState = TOUCH_STATE_REST;
                mAllowLongPress = false;
                mActivePointerId = INVALID_POINTER;
                releaseVelocityTracker();
                break;

            case MotionEvent.ACTION_POINTER_UP:
                onSecondaryPointerUp(ev);
                releaseVelocityTracker();
                break;
        }

        /*
         * The only time we want to intercept motion events is if we are in the
         * drag mode.
         */
        return mTouchState != TOUCH_STATE_REST;
    }

    protected void determineScrollingStart(MotionEvent ev) {
        determineScrollingStart(ev, 1.0f);
    }

    /*
     * Determines if we should change the touch state to start scrolling after the
     * user moves their touch point too far.
     */
    protected void determineScrollingStart(MotionEvent ev, float touchSlopScale) {
        /*
         * Locally do absolute value. mLastMotionX is set to the y value
         * of the down event.
         */
        final int pointerIndex = ev.findPointerIndex(mActivePointerId);
        if (pointerIndex == -1) {
            return;
        }
        final float x = ev.getX(pointerIndex);
        final float y = ev.getY(pointerIndex);
        final int xDiff = (int) Math.abs(x - mLastMotionX);
        final int yDiff = (int) Math.abs(y - mLastMotionY);

        final int touchSlop = Math.round(touchSlopScale * mTouchSlop);
        boolean xPaged = xDiff > mPagingTouchSlop;
        boolean xMoved = xDiff > touchSlop;
        boolean yMoved = yDiff > touchSlop;

        if (xMoved || xPaged || yMoved) {
            if (mUsePagingTouchSlop ? xPaged : xMoved) {
                // Scroll if the user moved far enough along the X axis
                mTouchState = TOUCH_STATE_SCROLLING;
                mTotalMotionX += Math.abs(mLastMotionX - x);
                mLastMotionX = x;
                mLastMotionXRemainder = 0;
                mTouchX = getScrollX();
                mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
                pageBeginMoving();
            }
            // Either way, cancel any pending longpress
            cancelCurrentPageLongPress();
        }
    }

    protected void cancelCurrentPageLongPress() {
        if (mAllowLongPress) {
            mAllowLongPress = false;
            // Try canceling the long press. It could also have been scheduled
            // by a distant descendant, so use the mAllowLongPress flag to block
            // everything
            final View currentPage = getPageAt(mCurrentPage);
            if (currentPage != null) {
                currentPage.cancelLongPress();
            }
        }
    }

    protected float getScrollProgress(int screenCenter, View v, int page) {
        final int halfScreenSize = getMeasuredWidth() / 2;

        int totalDistance = getScaledMeasuredWidth(v) + mPageSpacing;
        int delta = screenCenter - (getChildOffset(page) -
                getRelativeChildOffset(page) + halfScreenSize);

        float scrollProgress = delta / (totalDistance * 1.0f);
        scrollProgress = Math.min(scrollProgress, 1.0f);
        scrollProgress = Math.max(scrollProgress, -1.0f);
        return scrollProgress;
    }

    // This curve determines how the effect of scrolling over the limits of the page dimishes
    // as the user pulls further and further from the bounds
    private float overScrollInfluenceCurve(float f) {
        f -= 1.0f;
        return f * f * f + 1.0f;
    }

    protected void acceleratedOverScroll(float amount) {
        int screenSize = getMeasuredWidth();

        // We want to reach the max over scroll effect when the user has
        // over scrolled half the size of the screen
        float f = OVERSCROLL_ACCELERATE_FACTOR * (amount / screenSize);

        if (f == 0) return;

        // Clamp this factor, f, to -1 < f < 1
        if (Math.abs(f) >= 1) {
            f /= Math.abs(f);
        }

        int overScrollAmount = (int) Math.round(f * screenSize);
        if (amount < 0) {
            mOverScrollX = overScrollAmount;
            super.scrollTo(0, getScrollY());
        } else {
            mOverScrollX = mMaxScrollX + overScrollAmount;
            super.scrollTo(mMaxScrollX, getScrollY());
        }
        invalidate();
    }

    protected void dampedOverScroll(float amount) {
        int screenSize = getMeasuredWidth();

        float f = (amount / screenSize);

        if (f == 0) return;
        f = f / (Math.abs(f)) * (overScrollInfluenceCurve(Math.abs(f)));

        // Clamp this factor, f, to -1 < f < 1
        if (Math.abs(f) >= 1) {
            f /= Math.abs(f);
        }

        int overScrollAmount = (int) Math.round(OVERSCROLL_DAMP_FACTOR * f * screenSize);
        if (amount < 0) {
            mOverScrollX = overScrollAmount;
            super.scrollTo(0, getScrollY());
        } else {
            mOverScrollX = mMaxScrollX + overScrollAmount;
            super.scrollTo(mMaxScrollX, getScrollY());
        }
        invalidate();
    }

    protected void overScroll(float amount) {
        dampedOverScroll(amount);
    }

    protected float maxOverScroll() {
        // Using the formula in overScroll, assuming that f = 1.0 (which it should generally not
        // exceed). Used to find out how much extra wallpaper we need for the over scroll effect
        float f = 1.0f;
        f = f / (Math.abs(f)) * (overScrollInfluenceCurve(Math.abs(f)));
        return OVERSCROLL_DAMP_FACTOR * f;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        // Skip touch handling if there are no pages to swipe
        if (getChildCount() <= 0) return super.onTouchEvent(ev);

        acquireVelocityTrackerAndAddMovement(ev);

        final int action = ev.getAction();

        switch (action & MotionEvent.ACTION_MASK) {
        case MotionEvent.ACTION_DOWN:
            /*
             * If being flinged and user touches, stop the fling. isFinished
             * will be false if being flinged.
             */
            if (!mScroller.isFinished()) {
                mScroller.abortAnimation();
            }

            // Remember where the motion event started
            mDownMotionX = mLastMotionX = ev.getX();
            mLastMotionXRemainder = 0;
            mTotalMotionX = 0;
            mActivePointerId = ev.getPointerId(0);
            if (mTouchState == TOUCH_STATE_SCROLLING) {
                pageBeginMoving();
            }
            break;

        case MotionEvent.ACTION_MOVE:
            if (mTouchState == TOUCH_STATE_SCROLLING) {
                // Scroll to follow the motion event
                final int pointerIndex = ev.findPointerIndex(mActivePointerId);
                final float x = ev.getX(pointerIndex);
                final float deltaX = mLastMotionX + mLastMotionXRemainder - x;

                mTotalMotionX += Math.abs(deltaX);

                // Only scroll and update mLastMotionX if we have moved some discrete amount.  We
                // keep the remainder because we are actually testing if we've moved from the last
                // scrolled position (which is discrete).
                if (Math.abs(deltaX) >= 1.0f) {
                    mTouchX += deltaX;
                    mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
                    if (!mDeferScrollUpdate) {
                        scrollBy((int) deltaX, 0);
                        if (DEBUG) Log.d(TAG, "onTouchEvent().Scrolling: " + deltaX);
                    } else {
                        invalidate();
                    }
                    mLastMotionX = x;
                    mLastMotionXRemainder = deltaX - (int) deltaX;
                } else {
                    awakenScrollBars();
                }
            } else {
                determineScrollingStart(ev);
            }
            break;

        case MotionEvent.ACTION_UP:
            if (mTouchState == TOUCH_STATE_SCROLLING) {
                final int activePointerId = mActivePointerId;
                final int pointerIndex = ev.findPointerIndex(activePointerId);
                final float x = ev.getX(pointerIndex);
                final VelocityTracker velocityTracker = mVelocityTracker;
                velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                int velocityX = (int) velocityTracker.getXVelocity(activePointerId);
                final int deltaX = (int) (x - mDownMotionX);
                final int pageWidth = getScaledMeasuredWidth(getPageAt(mCurrentPage));
                boolean isSignificantMove = Math.abs(deltaX) > pageWidth *
                        SIGNIFICANT_MOVE_THRESHOLD;

                mTotalMotionX += Math.abs(mLastMotionX + mLastMotionXRemainder - x);

                boolean isFling = mTotalMotionX > MIN_LENGTH_FOR_FLING &&
                        Math.abs(velocityX) > mFlingThresholdVelocity;

                // In the case that the page is moved far to one direction and then is flung
                // in the opposite direction, we use a threshold to determine whether we should
                // just return to the starting page, or if we should skip one further.
                boolean returnToOriginalPage = false;
                if (Math.abs(deltaX) > pageWidth * RETURN_TO_ORIGINAL_PAGE_THRESHOLD &&
                        Math.signum(velocityX) != Math.signum(deltaX) && isFling) {
                    returnToOriginalPage = true;
                }

                int finalPage;
                // We give flings precedence over large moves, which is why we short-circuit our
                // test for a large move if a fling has been registered. That is, a large
                // move to the left and fling to the right will register as a fling to the right.
                final boolean isRtl = isLayoutRtl();
                boolean isDeltaXLeft = isRtl ? deltaX > 0 : deltaX < 0;
                boolean isVelocityXLeft = isRtl ? velocityX > 0 : velocityX < 0;
                if (((isSignificantMove && !isDeltaXLeft && !isFling) ||
                        (isFling && !isVelocityXLeft)) && mCurrentPage > 0) {
                    finalPage = returnToOriginalPage ? mCurrentPage : mCurrentPage - 1;
                    snapToPageWithVelocity(finalPage, velocityX);
                } else if (((isSignificantMove && isDeltaXLeft && !isFling) ||
                        (isFling && isVelocityXLeft)) &&
                        mCurrentPage < getChildCount() - 1) {
                    finalPage = returnToOriginalPage ? mCurrentPage : mCurrentPage + 1;
                    snapToPageWithVelocity(finalPage, velocityX);
                } else {
                    snapToDestination();
                }
            } else if (mTouchState == TOUCH_STATE_PREV_PAGE) {
                // at this point we have not moved beyond the touch slop
                // (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
                // we can just page
                int nextPage = Math.max(0, mCurrentPage - 1);
                if (nextPage != mCurrentPage) {
                    snapToPage(nextPage);
                } else {
                    snapToDestination();
                }
            } else if (mTouchState == TOUCH_STATE_NEXT_PAGE) {
                // at this point we have not moved beyond the touch slop
                // (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
                // we can just page
                int nextPage = Math.min(getChildCount() - 1, mCurrentPage + 1);
                if (nextPage != mCurrentPage) {
                    snapToPage(nextPage);
                } else {
                    snapToDestination();
                }
            } else {
                onUnhandledTap(ev);
            }
            mTouchState = TOUCH_STATE_REST;
            mActivePointerId = INVALID_POINTER;
            releaseVelocityTracker();
            break;

        case MotionEvent.ACTION_CANCEL:
            if (mTouchState == TOUCH_STATE_SCROLLING) {
                snapToDestination();
            }
            mTouchState = TOUCH_STATE_REST;
            mActivePointerId = INVALID_POINTER;
            releaseVelocityTracker();
            break;

        case MotionEvent.ACTION_POINTER_UP:
            onSecondaryPointerUp(ev);
            break;
        }

        return true;
    }

    @Override
    public boolean onGenericMotionEvent(MotionEvent event) {
        if ((event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) {
            switch (event.getAction()) {
                case MotionEvent.ACTION_SCROLL: {
                    // Handle mouse (or ext. device) by shifting the page depending on the scroll
                    final float vscroll;
                    final float hscroll;
                    if ((event.getMetaState() & KeyEvent.META_SHIFT_ON) != 0) {
                        vscroll = 0;
                        hscroll = event.getAxisValue(MotionEvent.AXIS_VSCROLL);
                    } else {
                        vscroll = -event.getAxisValue(MotionEvent.AXIS_VSCROLL);
                        hscroll = event.getAxisValue(MotionEvent.AXIS_HSCROLL);
                    }
                    if (hscroll != 0 || vscroll != 0) {
                        boolean isForwardScroll = isLayoutRtl() ? (hscroll < 0 || vscroll < 0)
                                                         : (hscroll > 0 || vscroll > 0);
                        if (isForwardScroll) {
                            scrollRight();
                        } else {
                            scrollLeft();
                        }
                        return true;
                    }
                }
            }
        }
        return super.onGenericMotionEvent(event);
    }

    private void acquireVelocityTrackerAndAddMovement(MotionEvent ev) {
        if (mVelocityTracker == null) {
            mVelocityTracker = VelocityTracker.obtain();
        }
        mVelocityTracker.addMovement(ev);
    }

    private void releaseVelocityTracker() {
        if (mVelocityTracker != null) {
            mVelocityTracker.recycle();
            mVelocityTracker = null;
        }
    }
    
    

    @Override
	protected void onDetachedFromWindow() {
		getContext().unregisterReceiver(mReceiver);
		super.onDetachedFromWindow();
	}

    private void onSecondaryPointerUp(MotionEvent ev) {
        final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >>
                MotionEvent.ACTION_POINTER_INDEX_SHIFT;
        final int pointerId = ev.getPointerId(pointerIndex);
        if (pointerId == mActivePointerId) {
            // This was our active pointer going up. Choose a new
            // active pointer and adjust accordingly.
            // TODO: Make this decision more intelligent.
            final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
            mLastMotionX = mDownMotionX = ev.getX(newPointerIndex);
            mLastMotionY = ev.getY(newPointerIndex);
            mLastMotionXRemainder = 0;
            mActivePointerId = ev.getPointerId(newPointerIndex);
            if (mVelocityTracker != null) {
                mVelocityTracker.clear();
            }
        }
    }

    protected void onUnhandledTap(MotionEvent ev) {}

    @Override
    public void requestChildFocus(View child, View focused) {
        super.requestChildFocus(child, focused);
        int page = indexToPage(indexOfChild(child));
        if (page >= 0 && page != getCurrentPage() && !isInTouchMode()) {
            snapToPage(page);
        }
    }

    protected int getChildIndexForRelativeOffset(int relativeOffset) {
        final boolean isRtl = isLayoutRtl();
        final int childCount = getChildCount();
        int left;
        int right;
        final int startIndex = isRtl ? childCount - 1 : 0;
        final int endIndex = isRtl ? -1 : childCount;
        final int delta = isRtl ? -1 : 1;
        for (int i = startIndex; i != endIndex; i += delta) {
            left = getRelativeChildOffset(i);
            right = (left + getScaledMeasuredWidth(getPageAt(i)));
            if (left <= relativeOffset && relativeOffset <= right) {
                return i;
            }
        }
        return -1;
    }

    protected int getChildWidth(int index) {
        // This functions are called enough times that it actually makes a difference in the
        // profiler -- so just inline the max() here
		
		//by cat null point bug
		if(getPageAt(index)==null){
			return 912;
		}    
		final int measuredWidth = getPageAt(index).getMeasuredWidth();
		final int minWidth = mMinimumWidth;
		return (minWidth > measuredWidth) ? minWidth : measuredWidth;	
		
    }

    int getPageNearestToCenterOfScreen() {
        int minDistanceFromScreenCenter = Integer.MAX_VALUE;
        int minDistanceFromScreenCenterIndex = -1;
        int screenCenter = getScrollX() + (getMeasuredWidth() / 2);
        final int childCount = getChildCount();
        for (int i = 0; i < childCount; ++i) {
            View layout = (View) getPageAt(i);
            int childWidth = getScaledMeasuredWidth(layout);
            int halfChildWidth = (childWidth / 2);
            int childCenter = getChildOffset(i) + halfChildWidth;
            int distanceFromScreenCenter = Math.abs(childCenter - screenCenter);
            if (distanceFromScreenCenter < minDistanceFromScreenCenter) {
                minDistanceFromScreenCenter = distanceFromScreenCenter;
                minDistanceFromScreenCenterIndex = i;
            }
        }
        return minDistanceFromScreenCenterIndex;
    }

    protected void snapToDestination() {
        snapToPage(getPageNearestToCenterOfScreen(), PAGE_SNAP_ANIMATION_DURATION);
    }

    private static class ScrollInterpolator implements Interpolator {
        public ScrollInterpolator() {
        }

        public float getInterpolation(float t) {
            t -= 1.0f;
            return t*t*t*t*t + 1;
        }
    }

    // We want the duration of the page snap animation to be influenced by the distance that
    // the screen has to travel, however, we don't want this duration to be effected in a
    // purely linear fashion. Instead, we use this method to moderate the effect that the distance
    // of travel has on the overall snap duration.
    float distanceInfluenceForSnapDuration(float f) {
        f -= 0.5f; // center the values about 0.
        f *= 0.3f * Math.PI / 2.0f;
        return (float) Math.sin(f);
    }

    protected void snapToPageWithVelocity(int whichPage, int velocity) {
        whichPage = Math.max(0, Math.min(whichPage, getChildCount() - 1));
        int halfScreenSize = getMeasuredWidth() / 2;

        if (DEBUG) Log.d(TAG, "snapToPage.getChildOffset(): " + getChildOffset(whichPage));
        if (DEBUG) Log.d(TAG, "snapToPageWithVelocity.getRelativeChildOffset(): "
                + getMeasuredWidth() + ", " + getChildWidth(whichPage));
        final int newX = getChildOffset(whichPage) - getRelativeChildOffset(whichPage);
        int delta = newX - mUnboundedScrollX;
        int duration = 0;

        if (Math.abs(velocity) < mMinFlingVelocity) {
            // If the velocity is low enough, then treat this more as an automatic page advance
            // as opposed to an apparent physical response to flinging
            snapToPage(whichPage, PAGE_SNAP_ANIMATION_DURATION);
            return;
        }

        // Here we compute a "distance" that will be used in the computation of the overall
        // snap duration. This is a function of the actual distance that needs to be traveled;
        // we keep this value close to half screen size in order to reduce the variance in snap
        // duration as a function of the distance the page needs to travel.
        float distanceRatio = Math.min(1f, 1.0f * Math.abs(delta) / (2 * halfScreenSize));
        float distance = halfScreenSize + halfScreenSize *
                distanceInfluenceForSnapDuration(distanceRatio);

        velocity = Math.abs(velocity);
        velocity = Math.max(mMinSnapVelocity, velocity);

        // we want the page's snap velocity to approximately match the velocity at which the
        // user flings, so we scale the duration by a value near to the derivative of the scroll
        // interpolator at zero, ie. 5. We use 4 to make it a little slower.
        duration = 4 * Math.round(1000 * Math.abs(distance / velocity));
        duration = Math.min(duration, MAX_PAGE_SNAP_DURATION);

        snapToPage(whichPage, delta, duration);
    }

    protected void snapToPage(int whichPage) {
        snapToPage(whichPage, PAGE_SNAP_ANIMATION_DURATION);
    }

    protected void snapToPage(int whichPage, int duration) {
        whichPage = Math.max(0, Math.min(whichPage, getPageCount() - 1));

        if (DEBUG) Log.d(TAG, "snapToPage.getChildOffset(): " + getChildOffset(whichPage));
        if (DEBUG) Log.d(TAG, "snapToPage.getRelativeChildOffset(): " + getMeasuredWidth() + ", " + getChildWidth(whichPage));
        int newX = getChildOffset(whichPage) - getRelativeChildOffset(whichPage);
        final int sX = mUnboundedScrollX;
        final int delta = newX - sX;
        snapToPage(whichPage, delta, duration);
    }

    protected void snapToPage(int whichPage, int delta, int duration) {
        mNextPage = whichPage;

        View focusedChild = getFocusedChild();
        if (focusedChild != null && whichPage != mCurrentPage && focusedChild == getPageAt(mCurrentPage)) {
            focusedChild.clearFocus();
        }

        pageBeginMoving();
        awakenScrollBars(duration);
        if (duration == 0) {
            duration = Math.abs(delta);
        }

        if (!mScroller.isFinished()) mScroller.abortAnimation();
        mScroller.startScroll(mUnboundedScrollX, 0, delta, 0, duration);

        // Load associated pages immediately if someone else is handling the scroll, otherwise defer loading associated pages until the scroll settles
        if (mDeferScrollUpdate) {
            loadAssociatedPages(mNextPage);
        } else {
            mDeferLoadAssociatedPagesUntilScrollCompletes = true;
        }
        notifyPageSwitchListener();
        invalidate();
    }

    public void scrollLeft() {
        if (mScroller.isFinished()) {
            if (mCurrentPage > 0) snapToPage(mCurrentPage - 1);
        } else {
            if (mNextPage > 0) snapToPage(mNextPage - 1);
        }
    }

    public void scrollRight() {
        if (mScroller.isFinished()) {
            if (mCurrentPage < getChildCount() -1) snapToPage(mCurrentPage + 1);
        } else {
            if (mNextPage < getChildCount() -1) snapToPage(mNextPage + 1);
        }
    }

    public int getPageForView(View v) {
        int result = -1;
        if (v != null) {
            ViewParent vp = v.getParent();
            int count = getChildCount();
            for (int i = 0; i < count; i++) {
                if (vp == getPageAt(i)) {
                    return i;
                }
            }
        }
        return result;
    }

    /**
     * @return True is long presses are still allowed for the current touch
     */
    public boolean allowLongPress() {
        return mAllowLongPress;
    }

    /**
     * Set true to allow long-press events to be triggered, usually checked by
     * {@link Launcher} to accept or block dpad-initiated long-presses.
     */
    public void setAllowLongPress(boolean allowLongPress) {
        mAllowLongPress = allowLongPress;
    }

    public static class SavedState extends BaseSavedState {
        int currentPage = -1;

        SavedState(Parcelable superState) {
            super(superState);
        }

        private SavedState(Parcel in) {
            super(in);
            currentPage = in.readInt();
        }

        @Override
        public void writeToParcel(Parcel out, int flags) {
            super.writeToParcel(out, flags);
            out.writeInt(currentPage);
        }

        public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {
            public SavedState createFromParcel(Parcel in) {
                return new SavedState(in);
            }

            public SavedState[] newArray(int size) {
                return new SavedState[size];
            }
        };
    }

    protected void loadAssociatedPages(int page) {
        loadAssociatedPages(page, false);
    }
    protected void loadAssociatedPages(int page, boolean immediateAndOnly) {
        if (mContentIsRefreshable) {
            final int count = getChildCount();
            if (page < count) {
                int lowerPageBound = getAssociatedLowerPageBound(page);
                int upperPageBound = getAssociatedUpperPageBound(page);
                if (DEBUG) Log.d(TAG, "loadAssociatedPages: " + lowerPageBound + "/" + upperPageBound);
                // First, clear any pages that should no longer be loaded
                for (int i = 0; i < count; ++i) {
                    Page layout = (Page) getPageAt(i);
                    if ((i < lowerPageBound) || (i > upperPageBound)) {
                        if (layout.getPageChildCount() > 0) {
                            layout.removeAllViewsOnPage();
                        }
                        mDirtyPageContent.set(i, true);
                    }
                }
                // Next, load any new pages
                for (int i = 0; i < count; ++i) {
                    if ((i != page) && immediateAndOnly) {
                        continue;
                    }
                    if (lowerPageBound <= i && i <= upperPageBound) {
                        if (mDirtyPageContent.get(i)) {
                            syncPageItems(i, (i == page) && immediateAndOnly);
                            mDirtyPageContent.set(i, false);
                        }
                    }
                }
            }
        }
    }

    protected int getAssociatedLowerPageBound(int page) {
        return Math.max(0, page - 1);
    }
    protected int getAssociatedUpperPageBound(int page) {
        final int count = getChildCount();
        return Math.min(page + 1, count - 1);
    }

    /**
     * This method is called ONLY to synchronize the number of pages that the paged view has.
     * To actually fill the pages with information, implement syncPageItems() below.  It is
     * guaranteed that syncPageItems() will be called for a particular page before it is shown,
     * and therefore, individual page items do not need to be updated in this method.
     */
    public abstract void syncPages();

    /**
     * This method is called to synchronize the items that are on a particular page.  If views on
     * the page can be reused, then they should be updated within this method.
     */
    public abstract void syncPageItems(int page, boolean immediate);

    protected void invalidatePageData() {
        invalidatePageData(-1, false);
    }
    protected void invalidatePageData(int currentPage) {
        invalidatePageData(currentPage, false);
    }
    protected void invalidatePageData(int currentPage, boolean immediateAndOnly) {
        if (!mIsDataReady)  return;

        if (mContentIsRefreshable) {
            // Force all scrolling-related behavior to end
            mScroller.forceFinished(true);
            mNextPage = INVALID_PAGE;

            // Update all the pages
            syncPages();

            // We must force a measure after we've loaded the pages to update the content width and to determine the full scroll width
            measure(MeasureSpec.makeMeasureSpec(getMeasuredWidth(), MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(getMeasuredHeight(), MeasureSpec.EXACTLY));

            // Set a new page as the current page if necessary
            if (currentPage > -1) {
                setCurrentPage(Math.min(getPageCount() - 1, currentPage));
            }

            // Mark each of the pages as dirty
            final int count = getChildCount();
            mDirtyPageContent.clear();
            for (int i = 0; i < count; ++i) {
                mDirtyPageContent.add(true);
            }

            // Load any pages that are necessary for the current window of views
            loadAssociatedPages(mCurrentPage, immediateAndOnly);
            requestLayout();
        }
    }

    protected View getScrollingIndicator() {
        // We use mHasScrollIndicator to prevent future lookups if there is no sibling indicator found
        if (mHasScrollIndicator && mScrollIndicator == null) {
            ViewGroup parent = (ViewGroup) getParent();
            if (parent != null) {
                mScrollIndicator = (View) (parent.findViewById(R.id.paged_view_indicator));
                mHasScrollIndicator = mScrollIndicator != null;
                if (mHasScrollIndicator) {
                    mScrollIndicator.setVisibility(View.VISIBLE);
                }
            }
            updateScrollingIndicatorBg();
        }
        return mScrollIndicator;
    }

    protected boolean isScrollingIndicatorEnabled() {
        return true;
    }

    Runnable hideScrollingIndicatorRunnable = new Runnable() {
        @Override
        public void run() {
            hideScrollingIndicator(false);
        }
    };
    protected void flashScrollingIndicator(boolean animated) {
        removeCallbacks(hideScrollingIndicatorRunnable);
        showScrollingIndicator(!animated);
        postDelayed(hideScrollingIndicatorRunnable, sScrollIndicatorFlashDuration);
    }

    protected void showScrollingIndicator(boolean immediately) {
        mShouldShowScrollIndicator = true;
        mShouldShowScrollIndicatorImmediately = true;
        if (getChildCount() <= 1) return;
        if (!isScrollingIndicatorEnabled()) return;

        mShouldShowScrollIndicator = false;
        getScrollingIndicator();
        if (mScrollIndicator != null) {
            // Fade the indicator in
            updateScrollingIndicatorPosition();
            mScrollIndicator.setVisibility(View.VISIBLE);
            cancelScrollingIndicatorAnimations();
            if (immediately || mScrollingPaused) {
                mScrollIndicator.setAlpha(1f);
            } else {
                mScrollIndicatorAnimator = LauncherAnimUtils.ofFloat(mScrollIndicator, "alpha", 1f);
                mScrollIndicatorAnimator.setDuration(sScrollIndicatorFadeInDuration);
                mScrollIndicatorAnimator.start();
            }
        }
    }

    protected void cancelScrollingIndicatorAnimations() {
        if (mScrollIndicatorAnimator != null) {
            mScrollIndicatorAnimator.cancel();
        }
    }

    protected void hideScrollingIndicator(boolean immediately) {
    	if(true)  return ;
        if (getChildCount() <= 1) return;
        if (!isScrollingIndicatorEnabled()) return;

        getScrollingIndicator();
        if (mScrollIndicator != null) {
            // Fade the indicator out
            updateScrollingIndicatorPosition();
            cancelScrollingIndicatorAnimations();
            if (immediately || mScrollingPaused) {
                mScrollIndicator.setVisibility(View.INVISIBLE);
                mScrollIndicator.setAlpha(0f);
            } else {
                mScrollIndicatorAnimator = LauncherAnimUtils.ofFloat(mScrollIndicator, "alpha", 0f);
                mScrollIndicatorAnimator.setDuration(sScrollIndicatorFadeOutDuration);
                mScrollIndicatorAnimator.addListener(new AnimatorListenerAdapter() {
                    private boolean cancelled = false;
                    @Override
                    public void onAnimationCancel(android.animation.Animator animation) {
                        cancelled = true;
                    }
                    @Override
                    public void onAnimationEnd(Animator animation) {
                        if (!cancelled) {
                            mScrollIndicator.setVisibility(View.INVISIBLE);
                        }
                    }
                });
                mScrollIndicatorAnimator.start();
            }
        }
    }
    /**
     * To be overridden by subclasses to determine whether the scroll indicator should stretch to
     * fill its space on the track or not.
     */
    protected boolean hasElasticScrollIndicator() {
        return true;
    }

    private void updateScrollingIndicator() {
        if (getChildCount() <= 1) return;
        if (!isScrollingIndicatorEnabled()) return;

        getScrollingIndicator();
        if (mScrollIndicator != null) {
            updateScrollingIndicatorPosition();
        }
        if (mShouldShowScrollIndicator) {
            showScrollingIndicator(mShouldShowScrollIndicatorImmediately);
        }
    }

    private void updateScrollingIndicatorPosition() {
        final boolean isRtl = isLayoutRtl();
        if (!isScrollingIndicatorEnabled()) return;
        if (mScrollIndicator == null) return;
        int numPages = getChildCount();
        int pageWidth =mScrollIndicatorBg.getMeasuredWidth();
        int trackWidth = pageWidth ;
        int indicatorWidth = mScrollIndicatorBg.getMeasuredWidth() ;
        float scrollPos = isRtl ? mMaxScrollX - getScrollX() : getScrollX();
        float offset = Math.max(0f, Math.min(1f, (float) scrollPos / mMaxScrollX));
        if (isRtl) {
            offset = 1f - offset;
        }
//        mScrollIndicator.setLeft(ll.getLeft());
        int indicatorSpace = trackWidth / numPages;
        int indicatorPos = (int) (offset * (trackWidth - indicatorSpace)) ;
        mScrollIndicator.setTranslationX(indicatorPos);
        
    }

    /* Accessibility */
    @Override
    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
        super.onInitializeAccessibilityNodeInfo(info);
        info.setScrollable(getPageCount() > 1);
        if (getCurrentPage() < getPageCount() - 1) {
            info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
        }
        if (getCurrentPage() > 0) {
            info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD);
        }
    }

    @Override
    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
        super.onInitializeAccessibilityEvent(event);
        event.setScrollable(true);
        if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED) {
            event.setFromIndex(mCurrentPage);
            event.setToIndex(mCurrentPage);
            event.setItemCount(getChildCount());
        }
    }

    @Override
    public boolean performAccessibilityAction(int action, Bundle arguments) {
        if (super.performAccessibilityAction(action, arguments)) {
            return true;
        }
        switch (action) {
            case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: {
                if (getCurrentPage() < getPageCount() - 1) {
                    scrollRight();
                    return true;
                }
            } break;
            case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD: {
                if (getCurrentPage() > 0) {
                    scrollLeft();
                    return true;
                }
            } break;
        }
        return false;
    }

    protected String getCurrentPageDescription() {
        return String.format(getContext().getString(R.string.default_scroll_format), getNextPage() + 1, getChildCount());
    }

    @Override
    public boolean onHoverEvent(android.view.MotionEvent event) {
        return true;
    }
    
    public void updateScrollingIndicatorBg(){
    	ViewGroup parent = (ViewGroup) getParent();
    	mScrollIndicatorBg = (LinearLayout) parent.findViewById(R.id.linearLayout_fav);
    	
        if(mScrollIndicatorBg!=null){
        	if (mScrollIndicatorBg.getChildCount() > 0)
        		mScrollIndicatorBg.removeAllViews();
        	Log.e(TAG, "getChildCount() ="+getChildCount());
        	for (int i = 0; i < getChildCount(); i++) {
        		ImageView iv = new ImageView(getContext());
        		LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        		iv.setLayoutParams(p);
        		iv.setBackgroundResource(R.drawable.point_n);
        		mScrollIndicatorBg.addView(iv);
        	}
        	mScrollIndicatorBg.postInvalidate();
        }
    }
}